Telephone system.



A, E. LUNDELL.

TELEPHONE SYSTEM.

APPLICATION man on. 20, I916.

Patented Nov. 12, 1918.

4 SHEETS-SHEET 1.

/Il/Il/I/ v Im en for: Aiken E Lunde/l.

A. E. LUNDELL.

TELEPHONE SYSTEM} APPUCATION FILED OCT. 20. me.

Patented Nov. 12; 1918.

4 SHEETSSHEET 2.

In yen for:

A/ben E Lunde/I.

A. E. LUNDELL.

TELEPHONE SYSTEM.

APPLICATION FILED OCT. 20. 1915.

1,284,392. v Patehted Nov. 12; 1918.

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Muenloki A. E-LUNDELL.

TELEPHONE SYSTEM.

APPLICATION FILED OCT- 2 I916- F 1 ,284,392. Patented Nov. 12,1918. 4 SHEETS-SHEET 4s.

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AIBEN e1" NEW is.

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TELEEHGLIE STEM.

To all whom it may concern."

Be itkncwn that Z, Alissa E. LUNDELL, a citizen cf the United States, residieg at New Ycik, iii the county of Bren? and State of New Y 01 1:, have invented certain-new mid useful Improvements in Teiephone Syscems of which the following is e iuii, cieaz', concise, and exact description.

This invention relates i0 telephone 921- idle direct teiephciie line, the reieasing means provided for the connector switch must be operated, if the desired direct line tests busy, but the operation of "such reieesizcg means must be delayed While testing piivetebrench exchange lines until an idle private creme exchange line has been found or the condition of'the iesfi private breech exchange line i133 been tested. Gniy if the iest line is busy, will the releasing means be operated.

It has been prepcsed in ihe terminal bank of the connector'tc identifi the terminals 015 all'ihe private branch exchenge iines except the last one by current cit" a certain polarity, and the termmeicf she East private branch exchange line and thetermineis of direct lines by a. certain other pcierity. Responsive to 'these different polarities, differentially Wound or a polarized rel-21y was provided to ccntrciin its contacts the cpemticncf the reieesin nieces, i y

In or er 23c cbv'ieie the necessity of identifying the various lines by cur exit of diifier em, polarities, it has been proposed to provide an errangemene in which e31 the Bees terminating at a connector switch are identified. by current of "she samepoierit In. 'such arrangements, however, separate meeiis are provided for controlling the tesiiiclg of private brench exchange linesanci separate means for cciitrciiing the testing of direct mes or 11 one; or i i so e ,1 1 *1 "i w (is two e mp c brushes are pi'cvicieci for eeci CJZAIAGCLQZ switch.

It 18 the obJeca oi the present invention to do ewe with the necessitv cf residin clifs ine-me of Letters Patent Appiicetion filed mickey-2 1916'.

icrentie with bran 1" cewen'h of di 11 mic cbjeci in iengemem in efif-J iines iermineteg at a connectcr identified-icy cm?- pcierity, e singie iiieeiis be he concececr switch for ceni the reieesing means 51, 1,116. 2, respectiveiy, diagram maticcii ieiep ione sysiei Qem playing on:

"in he 41gs e.- piurality cf sequence switches indicated. These secieence switches may be imiim' shown in the caiem c win. Ne. 1,127,808, sinuier operatic and function to 1 c rrespondin. eceencr switches shown in the pctenf: .ic Eeri 1%. 1,125,579.

Each cf the s mesrer conflict is immedieie e cve sequence em and indie: e

hundreds 511 which T2 of the segues-cc swiicis in strucizure to that ke cokis and fieldnie stei ere cpeo @1113 in the se quence switch gush-ans i eted in the 1's:-

erc-nce ciiurecters e ijccenvcei'eio and, there fore, inciiccie the steeping pc-si sions 'ci ihe se ue ee switches. 3. the oiher sequence swiicii contacts are open all pcsii iclcs except chose indicated by the reference cheiecw ters adjacent ihececc. The contace gm ernecil by each 0i the severe? seeue'nce swicciies are spareted from those governec; by tiic confines oi the siieeis c2 me ecii' sequence swi cii con'xeci; is i the drawings by a reference che' iuifli eris digit oi Whici. is she sen zinc-eds 'xiigiiof switch governiii The selecting s itciies, as her are of the type Wei incwn in the in the brush ler contact each one peii of driven pew-er drums which rotate n 'i {I :irecticne, iii-us M. i i J :2 heating cperesicn ciiiese switches have not been fully disclosed, since they are clearly shown and described in the patent to Lundell, No. 1,168,319, January 18, 1916.

The operators controlling device or keyboard and the registers or recording devices which are shown in Fig. 40f the drawing and a set of counting relays shown in Fig. 3, are similar in construction, arrangement and operation to those disclosed in the above mentioned Patent No. 1,168,319.

It is believed that the present invention will be best understood by establishing a connection from a calling subscriber at A to a called subscriber at B. When the calling subscriber removes his receiver from the switchhook, the line relay 112 is-actuated in the well-known manner to close' a local energizing circuit to light the lamp signal 113. This signal indicates to a connecting operator that a call has originated on this line. The operator then inserts an answerin plug 114 into the calling jack 115. This completes a circuit which may be traced from grounded battery, winding of relay 116,

sleeve of plug 114, sleeve of jack 115, the winding of cut-off relay 117 to ound. The cut-off relay is energized an operates to 'denergize the line relay 112 and the lamp signal 113. Simultaneously, relay 116 is opperated and closeda circuit to move the district sequence switch 100 out of position 1, which circuit extends from grounded battery, magnet of sequence switch 100, contact 102 (1), front contact and armature of relay 116, to ground. In position 2 of the sequence switch 100, a circuit is completed to 'move the cord finder sequence switch out of position 1 and into position 2 which is established from grounded battery, magnet of sequence switch 300, contact 302, conductor 134, contact 103 (2) to ground. As soon as sequence switch 300 leaves position 1, it

completes circuits (not shown) to associate an idle sending device with the cord circuit to which the calling line has been connected.

-Upon the extension of the calling lineto the cord, the operator depresses listening-in key 121 and thus telephonically connects her head set with the substation apparatus of the calling subscriber.

Whenthe operator has ascertained the number of the desired line, she depresses one of the hundred series of keys indicated at 409, one of the tens serie'sof keys at 410 and one of the units' series 'of' keys at 411 in accordance with the designation of'the desired line. In response to the depression of one of these keys in each of the series. as

to rotate until its operating circuit is interrupted at the back contact and armature of stop relay 402. This takes place when the stop relay 402 is energized. understood that the depression of one of the numeral keys 409 operates to connect ground to one of the contacts 408 of register 400. Assuming that numeral key 412 is depressed, then a ground connection will be established through depressed numeral key 412 to contact 408 (1). As soon as register 400 is rotated, in this case to position 1, the energizing circuit for the stop relay 402 is completed from grounded battery, relay 402, contact 408 (1) and depressed. key 412 to ground.

The operating circuit for-the register 500 may be similarly traced from grounded battery, contact 306, conductor 404, magnet of the register 500, back contact and armature It will be of the stop relay 406, conductor 403, to

glpound. In response to the completion of t is circuit the register 500 rotates until it assumes a position corresponding to the depressed tens-key at which time the stop relay 406 is energized to open the circuit just described. The energizing circuit for the relay 406 extends from grounded battery, conductor 417, winding of the stop relay 406, contact 414, key 415, to ground. The units register 600 is likewise. operated over a circuit traceable from grounded battery, contact 306, conductor 405, magnetof the register 600, ,pack contact and armature of stop relay 40 to ground. The units register 600 also rotates until the stop relay 407 .is energized over a circuit completed fromcontact 304 (2), conductor 120, contact 107 I (2 to 3), toground. As soon as relay 118 is energized it completes a circuit to move the sequence switch 100; out of position2.

This circuit extends ffipm grounded battery, magnet of sequence switch 100, cc

ductor 129, contact 106 (2), fr ontr -contac hand armatur; oi relay 118, to ,zuud. As soon reaches position 3, a locking circuit is com- ,pleted for relay 118 from grouuded'hattery, windin front contact and sit hand armature of relay 118, contact 1 (2 to 3), over the circuitpre iously traced for relay 118.

1'11 position 3 I 100, a circuit is completed for'the updrive magnet 123 which. extends from grounded battery, mageet 1233, contact 1'25 (3), front contact and right hand armature of relay .118, to ground. The selector switch 131 starts to move. its brushes 132, 133 and 135 over the groups of trunk terminals of the switch and to move commutator brush 126 over thefconducting segments of commutator 125. As the commutator brush 127 cu counters the ccuducting segments of comv conducting 'segmen I grounded battery, conductor 810, counting relay 311, back; contact and armature of relay $12, conductor 31%, register contact 113 (1), conductor 111, contact 2 (2), front contact and armature of stepping relay 308,

to ground. The lower-counting relay 311 attracts its armature, and closes a locking" circuit including the windings of relays 3'11 and $312. Re-lay 312, however, is short-circuited until the stepping relay 308 is shortcircuited by the shunt scribed as extending through the commutator125. The upper counting relay 312 then attracts its armature, whereupon a circuit is completed from grounded battery, conductor 319, lower zerocounting relay 315, front contact and armature of relay 312, conductor 314:, over the remainder of the circuit previously described, Relay 315 attracts its armature, and prepares a circuit for re.-

lay 309, but this relay is shorz cii'cuited until the stepping relay 308 again The upper zero counting relay 309 is then energized over a circuit which may be traced from grounded battery, conductor 310, relay 3155, relay 309, front contact and armature of relay 315, contact 305, to ground. Relay 309 attracts its armature and at its dceuergiaee.

outer armature interrupts the fundamentalcircuit previously described. At its inner armature and front contact'it completes a circuit to move the sequence switch 300 out of position circuit extends em grounded battery, magnetoi' sequence switch the district se uence switch.

- desired number,

clrcuit previously de- 380, front contact and inner structure of relay 309, contact 305 (2), to ground. Se quence switch 300 continues to move until it reaches position h reas n of a circuit completed through its .2 aste contact 301. When the sequence switch 3019 moved out of position 2, the chain of counting-relays locked up during the sendin of impulses corresponding to the hundre s digit of the are denergized. Whenthe upper zero counting relay 309 interrupts the fundamental circuit it causes relay 118 to deenergize and open the circult of magnet 123, whereupon the selector is arrested with its wipers in operative rela tionto agroup of trunk terminals correspending to the hundreds key depressed, which is key 112, in the case assumed. Relay 118 closes a circuit from ground, through its armature'and back-contact, sequence switch contact 106 (3), conductor 129 and the power magnet of sequence switch 100 to grounded battery for inovino this sequence switch into position 11. FVhile the sequence switch is moving from position 3 to yosition 11 the selector hunts for an idle trunk in the selected groupiin a manner described in Patent No. 1,168,319 and when an idle trunk is seized, the relay 229, which controls the release of the connector, is energized over a circuit extending from grounded battery,v winding of relay 229, conductor 13?, test terminal, and test brush 135 to ground. I y In position 11 of sequence switch 100 the fundamental circuit, previously described, is extended through the brushes 132 and 133 or" the first selector and the trunk line with which they are now in engagement, to the connector. As soon as this takes place the line relay 212 is energized over a circuit extending from grounded batter contact 209 '(1), over the upper side of t e line, brush of the first selector, contact 109, conductor 119, stepping relay 30$, outermost armature.

, and back contact of the upper zero counting ioo relay 309, contact 3041(4), conductor 120,

contact 108' 11), a brush of the first sel tor, lower si e of the line, Contact 210 (1 to 1), to ground. The relay 212 is energized and at its lefikhand armature completes a lockiiw circuit. which may be'traced'from grounded battery, lcft hand armature and iront contact of relay 212, cont'act209 (1 to 1), over the fundamental circuit just described; At tile ri lit-hand armature oire lay 212, s circuitis completed to move the sequence switch 220 OHlZOIf position 1. This clrcuit may he traced from grounded hattery, magnet of the sequence switch 200, contact 292 (1), right-hand armature ana iront contact of rela 212, to groundw ln POSltlOn '2 of the sequence switch, an operating circult for thclugh-sspeedup-drive magnet 213 i J R iscompieted H0111 grounded battery, mag .130

net 213, contact 203 (2), right-hand arma ture and front contact of relay 212, to ground. As: the commutator brush'2l6 in the upward movement of connector encoun ters aconducting segment 214, a circuit in shunt ofthe fundamental circuit for controlling the counting relays is completed from grounded battery, relay 212, left-hand armature and front contact ofthis relay, contact 208 (2), conducting segments 214: of commutator 215, commutator brush 216, contact 205 (10 to 8), to ground. The counting relays are again operated during the tens series of impulses in the manner previously described, and when the upper zero counting relay 309 is again energized a circuit is completed from grounded bat-" tery, magnet of sequence switch 300, front contact and armature of relay 309, contact 305 (4) to ground, to move this sequence switch out of position 4. Sequence switch 300 continues to rotate until it reaches position 6, by reason of a circuit completed through its master contact 301. At the close of the tens series of impulses;,the .brushes 236, 237 and 238 of the'connector are in operative relation to the terminals. of the desired group. The fundamental circuit is now interrupted at the outer armature and back contact of the upper zero counting relay309. The relay 212 thereupon dcenergizes, and completes a circuit to move the sequence switch 200 out of positioir'2. This circuit may be traced from grounded battery, magnet of sequence switch 200, tontaet 202 (2), right-hand armature and back contact of relay 212, to ground. The regis-' ter 600 now operates in a manner similar to the operation of register 400 to determine the first relay of a chain of counting relays which are actuated as theunits impulses are transmitted. The fundamental circuit is reestablished as soon as the relay 300 deene'rgizes and causes the relay 212 to be energized and to attract its armatures. This completes a circuit to'move the sequence switch 200 out of position 3, which may be traced from. grounded battery, magnet of sequence switch 200, contact 202 (3), righthand armature and front contact of relay 212, to ground. The energization of relay 212 also completes an operating circuit for the slow speed up-drive magnet 218. This circuit extends from grounded battery, magnet 218, contact 203 (4), right-hand armature and front contact of relay 212, to ground. This operation of the up-drive magnet places the brushes236, 237 and 238 of the connector in engagement with the desired line, or in engagement with the first of a group of P B. X. lines as the case may be. At the close of the directive movements of the connector switch, the fundamental circuit is again interrupted at the outer armature and contact of relay 309 and the relay switch 200 out of position 4 which iscompleted from grounded battery, 'magnetof sequence switch 200 contact 202 ,(4), right-. d back contact of relay;

hand armature an 212, to ground. Sequence switch 200 continues to move until it reaches position 7 by reason of a circuit completed at its master contact 201. Simultaneously with the energization of relay 309, the sequence switch 300 is moved from position 6 to its normal position by anjoperating'circuit previously described.

When the sequence switch 300 reaches position '8 after the sending device has completed its operation, a circuit is completed to move the sequence switch 100 out of position 11. This circuit may be traced from grounded battery, magnet of sequence switch; 100, contact 102 (11), conductor 136, contact 303 (8 to 15), to ground. The sequence switch 100 continues to move until it reaches position 16, by reason of an operating c1r-. cuit completed at its master contact 101.

In position 7 of the sequence switch 200,

test relay 219 is energized over a circuit which may be traced from grounded battery,

left-hand winding of'this relay, contact 206 (7), to ground. If the selected line is busy the relay 219 remains locked up in a manner that will hereinafter be described. At the left-hand armature of relay'219, a circuit is.

completed for moving the sequence switch 200 out of position 7. This circuit extends from grounded battery, magnet of sequence switch 200, contact 207 '(7), frontcontact and left-hand armature of relay 219, to ground. Sequence switch 200. continues to move until it reaches position 9, by reason of a circuit completed through the master contact 201 to ground. While the sequence switch 200 is moving through position 8 and while it is in position 9, the relay 219 will only remain energized whilebusy lines are encountered.

In the present arrangement direct lines or lines leading directly to subscribers and private branch exchange lines terminate at the connector switches. To successfully serve these two classes of lines, it is essential to ciated with the-test conductors of direct lines at the connector and with the test conductor" of the last RIB. X. line of the group;

' to the test teviuinois of These reieys the connector is testing be I c desired 1 condiiiion u'iii be indicated by rei."

sisal on test terminal. Tue source of this raised 1. moi indiv .ted st 1S spoiled like grounded battery throug a resistance 233 and contact. c

c onnectoi 2 by which line has been seized, It wiii be remembered that reiay 219 energized While sequence switch Was in position 7. With re ey 219 energized, a test circuit is completed. This circuit may he traced from grounded hette 2S2, resistance 233' :0 point Where the circuit. divides; one branch extends ihrough the test termiuei 238 oi the front connector, right-hand armature and Contact of relay 219, Winding of relay ground; other branch extends from point 23i through the relief sistance of the Winding of rein}; to

ground. The resistance oi reiuy is sufiiwent to prevent relay 222 from being shunted out. Relay 222 therefore attracts its annsturesend completes e cincuit to move the sequence switch 200 out of position 9. circuit may be traced from grounded cattery, of sequence switch 200, contact, (9), conductor 223, front Contact and armature re a Y contact 202 (9), conductor ieft-iiand armature and front contact of relay 219, to ground.

of reiey 219, contactis established.

' 212, to ground. Being; 219 is The sequence switch continues 'to move until it reaches position 12, by reason of circuit completed through its master contact 201.

s soon as the sequence switch 200 reeche position 16, s lockingcircuit This circuit 1 from grounded bette {10 hand front contact and curse ..i 1 10331 iOCEECi up until sequence switch 202 shes posi- 'tion $4. In position 12 a c1..cuit is completed for the down-drive or tceiease magto move the sequence J30 sequence switch 200, contact net 225. This circuit may be traced from grounded batten, magnet 225,'contaci 20s (12), conductor 22 1-, front conisct end lefthand emeture of relay 219, to ground. soon as the connecto switch is restored to its normed position, a circuit is compieted switch 206' from posi- This circuit. may be battery, magnetof 2o? (12 to tion 12 to position 16. traced from grounded conductor 230, normal contact ofcommutw tor 215, commutator .orush 231, contact 205 '(lOto 8), to ground. In position 16,2.

resistance are in shunt Withiveiy high 'rebusy tone is tmnsmitte to the operator in the well-known manner, through cont-act 210 (1c).

if the desired line is a busy P. B. X. line,

this condition Will also be indicated by branch of which extends through the test contact of the desired line to the test brush 238 of the connector, right-hand armature and front contact of relay 219, relay 222, to ground. The other branch of the circuit extends from noinn 222', through the low-resistance winding of relay 228, to ground. This relatively low resistance shunts. out,

222, so that 126.088 not attract its,

the relay armature. It will be remembered that the sequence switch is now in position 9. In this nosit-ion the lip-drive magnet 218 is energized to move the connector brushes 236, 237, 238 through their hunting movement. This circuit may be traced from grounded battery, magnet 218, back%ontact and armature of relay 222, contact 204 (9), conductor 22%, front contact and left-hand armature of relay 219, to ground. The connector switch continues to hunt until the re1ay'2l9 is deeuergized. This'takes place when the circuit extending from grounded cattery, left-hand Winding of relay 219, eon- ;tuct 206 (9 conducting segments 220, brush 221, hand armature and front contact of relay 219, to ground, is interrupted when the original energizing circuit of relay 219 is broken, due to the idle condition ofthe seiected line, and when the brush 221 cucounters an insuiated segment, after the counector brushes are properly centered. When ishe leit-hend armature of rciay 219 is reerected, e. circuit is completed to move the sequence switch 220 out of position 9. This ircuit. meg "be tweed from grounded hettery, magnet of sequence switch 200, contact 207 (9), hack ture of relay 219,

to ground. The sequence switch continues to move untii it reaches contact 204 (9), conductor 224, ieft Contact and ieft-hand arrow position 12 by reason of on operating cirswitch 200 out. 0; position 12, 18 completed. This circuit may be traced from grounded battery, ma net of to! contact 201. In positionsequence switch 200,,coz1tacc 201'" (12 iefthand oi-mature and back cont sot ofrelay 219, to ground. The sequence switch conhomes to move untli itresches posit on 15 by reason of a circuit completed at its mas- 15 the talking i conductors are extended through contacts 209 and 210 (15) to the selected line at the connector and while sequence switch 200 is being moved to this position ringing cur- 5 rent isapplied to the selected line in the well-known manner.

At the conclusion of the conv vcaj the supervisory relays 127 are energized in the well-known manner to complete local circuits for lamp signals (not shown). This indicates to the operator that the call has terminated, whereupon she removes plug 114 I from the jack 115. The relay 116 deenergizes and retracts its armature, whereupon a circuit is completed to move the sequence switch out ofposition 16. This circuit may be traced from grounded battery, magnet of sequence switch 100, contact 102 (12 to 16), armature andback contact of relay 116, to ground. The sequence switch 100 continues to move until it reaches position 18, by reason of an operating circuit completed at its master contact 101. In position 18 of this sequence switch, a circuit is completed for the downdrive-magnet 128, which maybe traced from grounded battery, magnet 128', contact 111 (18), to ground. vWhen-the selector switch hasreached its normal position, a circuit is completed. for moving the sequence switch from position 18 into position 1. This circuit may be traced from grounded battery, magnet of sequence switch 100, conductor 129, contact 106 (18), conductor 130, conducting segment of commutator 125, brush 126 in its normal position, to ground.

When'the brushes of the first selector are moved from the test terminal of the selected trunk, the'energiz'ingcircuit for relay 229 is interrupted. This relay, on deenergizing, 40 completes a circuit for moving the sequence switch 200 from position 15 to position 17,

traceable from grounded battery, magnet of sequence switch 200, contact 202 (15 to 16),"

armature and back contact of relay 229, to ground. Sequence switch 200 continues to move until it reaches position 18, by reason of a circuit completed at its master contact 201. In position 18 of the sequence switch 200 a circuit is completed for the down-drive magnet 225'. This circuit may be traced from grounded battery, magnet 225, contact 205 (18), to ground. When the connector reaches its normal position, a circu1 swi tch 200 out of position 18 into its normal position. This circuit may be traced from grounded battery, magnet of sequence switch 200, contact 202 (18), conductor 230, conducting segment of commutator 215, brush 231, contact 205 (10 to 8),'to ground.

It has been found in practice'that the test circuits will operate ,most satisfactorily when the relays and resistance coils included therein are adjusted to the following resist- 6 ances: relay 222 of five hundred ohms; the

is completed to move the sequencewindings of the relay 219 each having resistance of five hundred ohms; resistance of coil 233 being three hundred ohms; resistance of coil 233 being three hundred ohms; resistance of relay 235 being four hundred ohms; the resistance of relay 228 being one hundred ohms. It will be understood that these resistance values may be varied as best suits the needs of the service without departing from the spirit of this invention.

What is claimed is:

1. In a telephone system, an incoming I line, outgoing lines, a switch, means con trolled at a distant point for causing said switch to select a particular, outgoing line, releasing means for said switch, a test conductor associated with each of the outgoing lines and terminating in said switch, means for supplying to the terminals of all of said test conductors current of the same polarity, and a double wound relay controlled by means of one of its windings over said test conductors for causing the further operation of said first mentioned means and said releasing means.

2. In a telephone system, an incoming I line, outgoing lines, a switch, means controlled at a distant point for causing said switch to select ap'articular outgoing line, releasing means for said switch, a test conductor associated with each of the outgoing lines and terminating in said switch, means forsupplyin to the terminals of all of said, test' con uctors current of the same polarity, a relay controlled in part over test conductors of outgoing lines, and means controlled in part by said rela for causing the further operation and re ease of said switch.

3. In a telephone system, an incoming line, outgoing lines, means for rendering said outgoing lines busy, atestconductor associated with each of the outgoing lines, a switch, means controlled at a distant point 'for operating said switch to seize a paring the terminals of the test conductors associated with busy lines with current of the same polarity, releasing means for said switch, a relay controlled in part over the test conductors of the busy lines, and a marginal relay controlled by said first mentioned'relay' for causing the further operation and release of said switch.

4.. In a telephone exchange system, a switch having an active contact and .a plurality of passive contacts, means for supplying the latter with current of the same polarity, a variable operable sending de-, vice, means for causing said switch to seize any passive contact in accordance with the adjustment of such sending device, a release magnet for said switch, and a single means switch to engage the test means for controlling said 1,esa,ees

for controlling the actuation of said release magnet and the further operation of said switch,

5. In a telephone exchange system, a selectively operable switch, said switch being provided with passive and active contacts,

said passive contacts being connected to the same pole of battery and arranged for engagement by said active contacts, a release magnet for said switch, a relay for controlling the actuation of said release magnet in response to the engagement of a test contact, means controlled by said relay for preventing the actuation of said release magnet upon the engagement of a certain other test contact, an energizing circuit for said relay, and a holding circuit for said relay including an active contact of said switch.

6. In a telephone exchange system, a connector switch, releasing means for said connector switch, a plurality of lines belongingto two classes, atest conductor supplied with current of the same polarity associated with each of said plurality of lines, means for rendering any one of said lines busy, means for causing said connector switch to engage any one of said lines, means operative if the engaged line belongs to one class and is busy for immediately operating said releasing means, means operative if the engaged line belongs to the other class and tests busy for delaying the actuation of said releasing means until the connector has en gaged all the lines belonging to said other class and such lines are busy, and a single means for controlling said two last mentioned means.

7. In a telephone system, a plurality of lines, a plurality of selectively operable switches, a test conductor associated with each one of said lines, all of said test conductors being normally connected to the same pole of battery, means at each one of said switches for causing it to engage any one of said lines and itsassociated test consaid switches for causin it to engage any one of said lines and its associated test conductor, means operative thereupon Ior connecting the engaged test conductor to the for supplying'the testconductors 01 one contacts, a relay, means ductor means 0 erative thereu on tor con-' mating the engaged test conductor to the opposite pole of battery, relea ing means for each of said switches, meani'or releasing a switch which is caused to engage the test conductor associated with a certain line and connected to said opposite pole of battery, means for causing said last mentioned conductor of an other line if said switch was caused to engage a certain test conductor connected. to the opposite pole of battery, and a single last two means.

8. lines, a plurality of selectively operable switches, a test conductor associated with each one of said lines, all of said test condoctors being normally connected to the same pole of battery, meansat each one of In a telephone system, a plurality of group through one of their branches with current of a certain polarity, means including a relatively low resistance for supplying the test conductors be the other group through one oftheir branches with current of said certain polarity, means for supplying all said test conductors through their other branches with current of the opposite polarity, a connector switch, means for operating it to engage any one of said test conductors, releasing means for said switch, a

mar lnal rela arran ed to be connected to said test conductors during the operation of said connector switch, means operated directly by said relay when in circuit with a high resistance jor causing the release of said switch, and means controlled directly by said relay when in circuit with a low resistance for causing the further operation of said switch.

10.' in a telephone exchange system, a co nector switch, a movable contact and a pinrality or stationary contacts for said switch 7 a plurality of conductors each leading from one ole or bat-tsto each. 0 said stationar for connecting said relay to the movable contact of said switch, means for rendering all said stationary contacts busy, means for operating said switch to more its movable contact onto one off said said stationary contacts, releasing-means for said movable contact actuated under control of said relay said last mentioned stationary contact tests busy, means for moving said movable contact into engagement with ano her one of said stationary contacts, automatic rneans' operative under the direct control of said relay if said last mentioned stationary contact is busy for causing said movable contact t9; move over a group of said stationary contacts, means also controlled directly by said relay for causing the operation at said releasing means to terminote the last mentioned operation of said movable contact only if the last stationary contact ct said group is busy.

11. In a telephone system, a switch having active contacts vincluding a single test contact and a plurality of passive contacts,

outgoing lines and associated test conductors terminating in said passive contacts, means for' supplying current of the same polarity to the contacts of all of said test conductors, means controlled from a distant point for causing said switch to seize a particular. outgoing line, releasing mechanism for said switch, means controlled over said test conductors for efiecting the automatic hunting operation and release of said switch,

and an operating and holding circuit for said last mentioned means.

12. In a telephone system, a switch having active contacts including a single test contact and a plurality of passive contacts, outgoing lines and associated test conductors terminating in said passive contacts, means ."for supplying current of'the same polarity .to the contacts of all of said test conductors, :ineans controlled from a distant point. for

l'caus ing said switch to seize a particular outgoing line, releasing mechanism for said switch, ,electroma etic' means controlled 4 over said test con uctors for affecting the automatic hunting operation and release of said switch, and means local to said switch for initially operating said electromagnetic means.

13. In a telephone system, a switch having active contacts including a single test contact and a plurality of passive contacts, outgoing lines and associated test conductors terminating in said passive contacts, means. for supplying current of the same polarity.

to the contacts of all of said test conductors, means controlled from a distant point for causing saidswltch to some a particular outgoing line, releasing mechanism for said ALBEN E. LUNDELL- 

